This invention has for its object to provide a device for forming a compact single-row layer of a given number of rodlike articles.
The invention relates, in particular, to machines for packing cigarettes or other similar rodlike articles, in which the cigarettes to be packed are composed in blocks, each of which consists of a certain number of single layers of cigarettes.
Typical, in this connection, is the block of 20 cigarettes, composed of three superimposed layers of cigarettes, respectively of seven, six and again seven cigarettes.
In a certain type of packing machines, predetermined single layers of cigarettes are composed in separate forming stations and are subsequently brought together and combined with each other, so as to obtain the desired block, ready for packing.
In the machines of the above type, for the composition of a single layer of n cigarettes, use is made of groups of n vertical or subvertical feeding channels or passage-ways, arranged close to each other, which lead to the row forming station, consisting substantially of a collecting chamber delimited by a bottom plate which stops the cigarettes at the outlet of the channels.
Presently, the partition walls which delimit the feeding channels are made so as to have their ends close to the cigarette stop plate, or are spaced away from the said plate, at a distance slightly greater than the cigarette diameter. When all of the feeding channels terminate close to the cigarette stop plate in the row-forming station, the greater width of the feeding channels in relation to the cigarette diameter, and the thickness of the partitions cause the formation of clearances between the cigarettes of the row being formed, at the moment in which said layer is ejected from the said forming station, for transfer into the receiving means.
Due to these clearances, which must be taken up, the transfer of the cigarettes into the receiving means involves the intermediary of a mouth type compactor, with decreasing section in the direction of movement of the cigarettes.
When instead the partition walls terminate spaced away from the bottom plate of the forming station, the clearances are taken up in the same forming station by means of side pushers of known type, which move laterally close to each other the cigarettes of the single layer or row being composed.
However, this side approach of the cigarettes of the row involves certain inconveniences, specially when the number of feeding channels is high and the total value of the clearances between the cigarettes corresponds to the diameter of a cigarette.
In fact, when these conditions occur, the cigarettes transferred by the feeding channels on the station stop plate, can occasionally get close to each other, against the outer wall of either one of the channels located at the extremities of the row, pushed by the overlying cigarettes which descend in the feeding channels. In this eventuality, the cigarette in either one of the extreme channels, which cigarette should be superposed on the one already deposited on the bottom plate, finds below a free space which allows it to descend to such an extent as to be pinched and, consequently, be damaged by the side pusher in its compacting motion. Obviously, the higher the number of cigarettes in a row, the greater is the above free space.
In the devices for composing numbered layers of cigarettes, in which the cigarettes descend along feeding channels which terminate at a certain distance from the row forming plate, the present invention is aimed at obviating the mentioned inconvenience of the pinching of some overlying cigarettes in the side feeding channels. For this purpose, the improvement comprises extending the partition wall which is in correspondence with the middle of the bundle of feeding channels leading to the forming chamber down to the composition plate so as to divide the cigarette row being formed into two parts possibly numerically equal or almost equal to each other. This arrangement divides between these two parts the total value of the side clearances between the cigarettes thereby avoiding the creation of an empty space which is sufficiently large for an overlying cigarette to fall down into the row and be pinched by one of the side pushers.
Preferably, the extreme lower edge of the middle partition wall fits into a groove of the bottom plate of the cigarette row forming chamber.
If the row being composed contains an even number of cigarettes, and, for instance, it is a row of six cigarettes, the partition wall will be right in the middle, and also exactly vertical. The partition wall in its terminal part, is made very thin in order not to considerably affect the clearance between the cigarettes of the row.
If, on the other hand, the row being composed contains an odd number of cigarettes, for instance, a row of 7 cigarettes, the partition wall will be only approximately intermediate and will divide the row into two parts, one containing four cigarettes and the other three. In this case, the extension portion by which the partition engages the bottom plate is preferably inclined in a direction away from the row portion in which the number of cigarettes is greater by one unit.